Microstructure and electric response of Li,Sn co-doped NiO ceramics

Processing and Application of Ceramics

Tusheng He¹  Yang Liu¹  Jiecheng Zeng¹ 

[1] School of Civil Engineering, Shaoguan University, Shaoguan 512005, China;

关键词: grain boundaries;    dielectric response;    Maxwell-Wagner polarization;    heterogeneous structure;   

DOI  :  10.2298/PAC1901044Z

来源: DOAJ

【 摘 要 】

Phase composition, microstructure and electric response of Li0.05SnxNi0.95 – xO (x = 0, 0.025, 0.05, 0.1) ceramics were systematically investigated. Colossal dielectric permittivity (>5000) is observed in the frequency range of 102–105 Hz at room temperature which becomes highly frequency-independent with increasing temperature. Secondary Sn-rich phase is detected in the grain boundary regions and it has a remarkable influence on the dielectric properties. Impedance spectroscopy analysis demonstrates that the microstructure is electrically heterogeneous, consisting of semiconducting grain and insulating grain boundary. Defect dipoles or polyvalent cations induced at high temperature may activate an electron hopping process under electric field, resulting in the enhancements of grain conductivity and polarization effect. This behaviour should be considered as the origin of the observed dielectric response.

【 授权许可】

Unknown